1. Field
Exemplary embodiments of the present invention relate to an analog to digital converting device, and more particularly, to an analog to digital converting device for converting an image signal into a digital signal.
2. Description of the Related Art
An analog to digital converter converts an analog signal into a digital signal. The analog to digital converter is necessarily used in a device for processing a digital signal, for example, an image sensor which receives an optical signal from outside, converts the received signal into a digital signal, and processes the digital signal. That is, the image sensor includes a pixel array for receiving an optical signal, and analog to digital converters provided at each column of the pixel array.
The image sensor additionally includes a capacitor for removing an offset voltage of a comparator, flicker noise, and noise contained in the reset voltage of pixel output, and stores the reset voltage of the pixel output and the offset voltage in the capacitor.
A reference document, Korean Patent Publication No. 2011-0104178, describes a converter which includes a capacitor array to convert an analog signal into a digital signal.